Our studies have been directed towards the development of an immunodiagnostic assay for the early detection of bladder cancer. In order to meet this objective, we have been involved in the isolation and characterization of tumor associated antigens (TAA) in urine from patients with bladder cancer. In early work, we were able to utilize a rabbit antiserum produced to a bladder tumor tissue extract to localize TAA in Sephadex G-150 elution profiles of urine from patients with bladder cancer. Subsequently, an antiserum was produced against this TAA cancer urine fraction (anti-CU). After absorption with normal urine and plasma, anti-CU was reacted in gel diffusion (GD) and complement fixation (CF) assays against various urine samples. In GD none of the urine from normal individuals (n equals 23), 37% of the urines from patients with urinary tract infection (UTI) (n equals 24) and 61% of urines from patients with papillomas and in situ carcinomas (n equals 13), and 95% of urines from patients with bladder cancer (n equals 30) were positive. In CF assays urines from patients with papillomas through grade IV cancers (n-53) showed a mean 50% CF at 30 micron protein, patients with UTI (n equals 29) showed a mean 50% CF at 150 micron protein and all but 6 urines from normal individuals (n equals greater than 30) showed 50% CF (mean valve) at 140 micron protein. Thus, these results suggest that TAA are present in CU. Current studies involve the further resolution of these TAA by isoelectric focusing (IEF) and ion-exchange chromatography. When normal urine, plasma, UTI and CU were compared in analytical IEF, urine specific components were noted, especially at low isoelectric points (3.0-3.5). TAA bands were not observed by this method. When various Cu fractions obtained by preparative IEF were assayed by the fused rocket immunoelectrophoretic technique utilizing anti-CU absorbed with normal plasma and urine TAA rockets were observed. Additional rockets were present which were common to both CU and UTI urine. The method of hydroxyapatite chromatography (HAC) is being utilized for the continued purification of these TAA. TAA elute at both 0.35M and 0.6M phosphate concentrations less than 0.2M. Currently we are producing antisera to various tumor associated antigenic IEF and H (Text Truncated - Exceeds Capacity)